Has anyone ever incubated OLD eggs?

I set some of my WLxRIR eggs on 11/5 with my thanksgiving hatch eggs and these eggs were i bet a month and a half to 2 months old. when i found the nest there were 20 eggs in it. i tried to let my hens set the eggs but no luck with that so i took 18 out of the 20 and put them in the bator.( needless to say none of them made it to hatch time.) the other 2 i marked and put back in the nest. after about 2 weeks i gathered them all up again because i wanted to put them in the bator well after the kids got ahold of them and busted some i had 7 eggs from my WL and 2 from my OEGB. 2 of the eggs were my OLD marked eggs. and believe it or not they are due to hatch thursday.... which really surprises me because i fully expected them to quit if they were even viable..

anyway i was wondering if anyone else has hatched out otr tried to hatch OLD eggs and what your experiences were with this.

The longest I've ever waited to incubate eggs was just over 2 weeks. Three showed development, but only one hatched.
If the eggs are from your hens, why not just gather some fresh ones and throw out the old eggs?
I wouldn't bother with the old eggs when fresh eggs are available.

Storage timeIdeally, eggs should be set in the incubator as soon after gathering as possible to maintain egg quality. If eggs are to be stored before incubation, the best hatchability occurs when eggs are stored for less than 7 days from the time they were laid. However, some species are more sensitive to storage than other species. Hatchability decreases rapidly in eggs held in storage for more than 10 days. Storing eggs longer than 2 weeks also can extend the normal incubation time as much as 1 day.
Temperature and humidity during storageFertile eggs should be stored at a dry bulb, normal temperature between 55 degrees F and 65 degrees F, or 13 degrees C and 18 degrees C. Embryos will begin to develop abnormally, weaken and die if the temperature is too high. A low temperature also causes high embryo mortality. Storage temperature should never exceed 72 degrees F (22 degrees C) and never go below 46 degrees F (8 degrees C). Egg storage at room temperature or at normal refrigerator temperatures (32 degrees F to 40 degrees F) is not acceptable because hatchability decreases.

I have hatched eggs that were a month old. I did it by mistake. Boy was i surprised. I now collect for three weeks before incubating. I candle three or four days later and seperate the none developing ones in a differant tray then after a week i trash the ones not developing.

I gathered up 7 eggs over a 4 day period and gave them to a silky to sit on. I left them there for over a week but she had no interest to sit on them. I was also trying to get a duck to go broody, so after that week I took 4 of those eggs and put in the duck nest. Well after another week and the duck nest starting to get full of eggs I pulled the 4 chicken eggs out, took the remaining three eggs that I had left in the original nest and was going to throw them away. When I got to the house I thought "what the heck, I will put them in the incubator and see if anything happens. All 7 developed and 6 hatched. The only one that did not hatch was fully developed but did not pierce the airsack. The eggs were pushing three weeks old and were left outside, Temps varied from the 60's to the 80's during that time.

Paganbird: its not that i didn't have fresh eggs available to incubate i was just wondering if they would still develop after sitting around for that long. they did and when i candled last night they were doing great. it seems the viable eggs will hold alot longer than we think. the hatchability of these older eggs probably decrease but it is still able to be done. so far i have 9 eggs that were set when all of them were at least a month old and every one of them have made it to lockdown. we will see if they hatch by this weekend and how strong the chicks are.

I just don't bother with eggs that may give me lower hatch rates. I prefer to optimize my chances of a high percentage hatch and healthy, strong chicks. I don't doubt that hatching 'old' eggs can be done - it's just not for me.
There are too many factors to consider... storage temperature, storage area, were the eggs turned, cleanliness of the shell, etc.
Good luck with your chicks. I hope they do well.